鄱阳湖湿地剖面土壤碳氮磷化学计量比沿高程梯度的变化特征  

Variation Characteristics of Carbon,Nitrogen and Phosphorus Stoichiometry in Soil Profiles Along Elevation Gradient in Poyang Lake Wetland

作　　者：徐晨瀛 胡启武[1,2] 邹素珍 叶家飞 汪晓倩 薛文婧 廉欣 任琼[3] 尧波[1,2] XU Chenying;HU Qiwu;ZOU Suzhen;YE Jiafei;WANG Xiaoqian;XUE Wenjing;LIAN Xin;REN Qiong;YAO Bo(School of Geography and Environment,Jiangxi Normal University,Nanchang 330022,China;Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education,Jiangxi Normal University,Nanchang 330022,China;Jiangxi Academy of Forestry,Nanchang 330032,China)

机构地区：[1]江西师范大学地理与环境学院,江西南昌330022 [2]江西师范大学,鄱阳湖湿地与流域研究教育部重点实验室,江西南昌330022 [3]江西省林业科学院,江西南昌330032

出　　处：《环境科学研究》2024年第11期2514-2525,共12页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.32060275,32360302);2022年中央财政湿地保护与恢复补助江西省湖泊湿地固碳增汇关键技术示范项目。

摘　　要：深入研究土壤碳氮磷化学计量特征有助于判断土壤营养状况以及养分间的耦合关系。为探究湿地剖面尺度的土壤化学计量特征分布规律及调控机制,在鄱阳湖南矶湿地国家级自然保护区内,沿高程设置高滩、中滩、低滩和泥滩4个梯度采集土壤样品,测定了不同高程0~100cm剖面土壤的理化性状及碳氮磷化学计量比。结果表明:鄱阳湖南矶湿地国家级自然保护区内不同高程0~100 cm剖面土壤有机碳(SOC)、全氮(TN)、全磷(TP)的平均含量在春季分别为(11.38±0.73)(1.43±0.12)和(0.54±0.03)g/kg,在秋季分别为(12.79±0.55)(1.13±0.03)和(0.40±0.01)g/kg,春秋两季0~10 cm深度的SOC、TP含量随高程的降低而减少,而两季0~10 cm深度的TN含量随高程的降低先增加后减少,两季SOC、TN和TP含量的剖面分布均未随高程的变化而改变。春季和秋季不同高程0~100 cm剖面土壤C/N/P分别为21.07∶2.64∶1和31.58∶2.77∶1,随高程的降低,仅两季0~10 cm深度的C/P和N/P呈上升趋势;而春季70~100 cm深度和秋季10~50 cm深度的C/N,以及春秋两季70~100 cm深度的C/P和50~70 cm深度的N/P均呈下降趋势。冗余分析和结构方程模型表明,SOC、TN、TP、pH和土壤水分(SM)是影响鄱阳湖湿地土壤碳氮磷化学计量比沿高程变化的主要因子,高程、季节、土壤深度通过改变SM和pH进而驱动SOC、TN、TP含量发生变化来调控碳氮磷化学计量比。研究显示,在气候持续暖干化背景下,鄱阳湖湿地不同土壤深度的养分限制状况会存在差异化转变,即表层土壤N的限制程度会加重而深层土壤N的限制会得到缓解。A detailed investigation of soil carbon(C),nitrogen(N),and phosphorus(P)stoichiometry is crucial for evaluating nutrient status and their coupling relationships.To explore the distribution patterns and regulatory mechanisms of soil nutrient stoichiometry at the profile scale,soil samples were collected along four elevation gradients(high beach,medium beach,low beach,and mud beach)in the Nanji Wetland National Nature Reserve of Poyang Lake.The physicochemical properties and the C,N and P stoichiometric ratios of the 0-100 cm soil profiles at different elevations were analyzed.The results indicated that the average contents of soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP)in the 0-100 cm soil profiles at different elevations were(11.38±0.73),(1.43±0.12)and(0.54±0.03)g/kg in spring,and(12.79±0.55),(1.13±0.03)and(0.40±0.01)g/kg in autumn,respectively.In the 0-10 cm depth,SOC and TP contents decreased with decreasing elevation in spring and autumn,whereas TN content increased and then decreased with decreasing elevation in both seasons.However,the distribution of SOC,TN and TP contents did not vary with elevation in both seasons.The C/N/P ratios in the 0-100 cm soil profiles at different elevations in spring and autumn were 21.07∶2.64∶1 and 31.58∶2.77∶1,respectively.With decreasing elevation,only the C/P and N/P ratios in the 0-10 cm depth showed an upward trend in both seasons,while the C/N ratios in the 70-100 cm depth in spring and the 10-50 cm depth in autumn,as well as the C/P ratios in the 70-100 cm depth and the N/P ratio in the 50-70 cm depth in both seasons showed a downward trend.Redundancy analysis revealed that SOC,TN,TP,pH and soil moisture(SM)were the main factors influencing C,N and P stoichiometry along the elevation.Structural equation modeling further indicated that elevation,season,and soil depth drove changes in SOC,TN and TP contents by altering SM and pH,thereby regulating the C,N and P stoichiometric ratios.Under the background of continuous warming and drying

关 键 词：生态化学计量比 剖面分布 高程 湿地 鄱阳湖 

分 类 号：X703[环境科学与工程—环境工程]